Parallel_Systems_1a Shared Memory Machines 1. [6 points] a….

Parallel_Systems_1a Shared Memory Machines 1. a. You are trying to explain the principles of sequential consistency and cache coherence to your friend. Your friend claims that cache coherence implies sequential consistency. Do you agree with your friend’s claim? If not, state how you will convince your friend that they are not the same. 

Parallel_Systems_3b M.E.Lock The context for this question i…

Parallel_Systems_3b M.E.Lock The context for this question is the same as the previous question: The Linux kernel historically used a ticket spin lock on multiprocessor systems. In 2016, Linux patch introduced a “qspinlock”, which is a “hybrid” design drawing inspiration from queue-based locks (MCS) and the old ticket lock.  “qspinlock” is built based on a linked-list lock. However, the first spinner (next-in-line thread) spins on a lock bit instead of carrying a node structure from lock to unlock. When more contenting thread arrives, the first spinner pays the overhead to revert back to spin on the node structure and queues additional threads in a linked list. b. Describe a scenario when either a ticket lock or a pure queue-based lock may outperform qspinlock. Explain why.